1. Field of the Invention
This invention is related to electrical terminals and is especially related to female electrical terminals that are matable with a male or pin terminal to form a disconnectable electrical connection between two electrical conductors. More specifically this invention is related to an electrical terminal in which a backup spring is used to support the connection to the mating male or pin terminal.
2. Description of the Prior Art
Although most prior art female electrical terminals are stamped and formed from a single member, some prior art female terminals do employ a composite structure in which a separate spring member is used to provide the spring force for engaging a mating male or pin terminal. Typical female terminals of this type employ a spring member of a highly resilient metal different from the material forming the remainder of the female terminal. An example of a terminal of this type is shown in U.S. Pat. No. 5,441,428, which discloses a terminal having a plate section disposed within a square or rectangular cylindrical contact portion. The plate section is bowed and is supported at its opposite ends by one wall of the cylindrical contact section. When a pin terminal is inserted the plate section is deflected and one free end of the plate section slides relative to the wall of the cylindrical contact on which the bowed plate section is supported. It appears that this separate resilient plate section provides most if not all of the contact force exerted on the mating pin or male terminal and therefore should provide the best electrical interface. Multiple electrical contacts must however be formed between this interface with the male terminal and the conductor to which the female terminal is attached.
Another approach for using dissimilar materials to form a composite female electrical terminal is shown in U.S. Pat. No. 5,246,390. In the terminal disclosed therein, a backup spring body is formed on the outside of contact spring arms that in turn extend from a wire termination portion of the two piece terminal. The outer backup spring body has a box shape with outer spring arms. To reduce insertion force when a mating tab is inserted, backup spring arms are held by spacing means at a minimum spacing from each other so that the contact spring arms come into abutment with the backup arms only after having been spread apart to a predetermined distance.